In the prior art, printing devices are known in which ink applied on an ink ribbon is transferred to a printing medium for printing by controlling energization of heater elements provided to a thermal head. Such a printing device is described in, for example, Unexamined Japanese Patent Application Kokai Publication No. 2011-062896.
In a thermal transfer printing device as described above, if an excessively high energy is applied to the ink ribbon, the ink ribbon may be damaged and consequently the print quality may be deteriorated. Particularly, when a phenomenon called broken ribbon in which an ink ribbon melts and breaks occurs, the printing itself stops.